Armstrong's vehement denial of the claim made by current USADA chief executive Travis Tygart, came in the second installment of his pre-recorded interview, which aired on Friday.

"This is another personal attack on Travis Tygart and the United States Anti-Doping Agency," Madden, chief executive of the agency from 2000–2007, told the New York Daily News. Tygart said in an interview with Showtime television's 60 Minutes Sports last week that an Armstrong representative called the agency in 2004 and offered a $250,000 "donation."

"That is not true," Armstrong told Winfrey, telling her he "asked around" among his camp to see if someone had made the offer without his knowledge. "That's a lot of money," Armstrong said. "I would know."

But Madden, who hasn't commented publicly on doping matters since his tenure at USADA ended, told both ESPN.com and the Daily News that he remembered the day that Tygart, then USADA's general counsel, received the call.

"Travis received a telephone call from one of Lance's closest representatives, who offered to make a contribution to USADA," Madden said. He said Tygart reported the call to him, and "within 30 seconds" Madden told Tygart to call back and reject the offer, since a donation from a person who could be drug-tested by the agency would be improper.

A similar six-figure donation by Armstrong to the International Cycling Union (UCI) has become a point of contention in the governing body's handling of Armstrong, with suggestions it was a pay-off.

Madden declined to identify the person who made the phone call to Tygart, saying he couldn't because of the U.S. federal whistleblower lawsuit filed by cyclist Floyd Landis that names Armstrong and several business associates as defendants.

That's not the only legal action Armstrong is facing. The Sunday Times is suing Armstrong for more than $1.6 million over a libel payment made to him in 2006. SCA Promotions, a Texas insurance company that paid bonuses to Armstrong for multiple Tour de France titles, has threatened to sue to get that money back. The firm tried to withhold payment because of doping allegations against Armstrong then, but the cyclist sued and won.

The first installment of Armstrong's interview with Winfrey included the American's first public admission—after years of vehement denials—that he used an array of performance enhancing drugs in winning a record seven Tour de France titles from 1999–2005. The belated admission comes three months after USADA issued a devastating 1,000-page report detailing the doping program in Armstrong's US Postal Service team, stripping him of his Tour titles and banning him for life from competition.